The present invention relates generally to semiconductor sensor devices and, more particularly to a method of assembling a pressure sensor device.
Pressure sensor devices use pressure-sensing dies (a.k.a. P-cells), such as piezo-resistive transducers (PRTs) and parameterized layout cells, to detect ambient atmospheric pressure. Pressure-sensing dies are referred to herein as P-cells; however, it should be understood that any suitable pressure-sensing die may be used.
P-cells are susceptible to damage during assembly and use. P-cells cannot be encapsulated in conventional mold compound because that would impede their functionality. Instead, P-cells are placed within device cavities and covered with a pressure-sensitive gel that protects the P-cells from damage during assembly and use, while still enabling the dies to function properly.
Conventional cavity-fill pressure sensor devices use bond wires to connect the P-cell to a master control unit (MCU) die also located within the device cavity. In addition, pressure sensor devices often include a gravity-sensing (G-cell) die that also is connected to the MCU with bond wires. As a result, the cavity must be large enough to accommodate the various dies as well as the bond wires interconnecting those dies. The large cavity requires more pressure-sensitive gel, which is relatively expensive, thereby increasing the cost of assembly.